The present invention relates to oligomeric and/or polymeric precursor stages of polyoxazoles as well as to a method for preparing these precursor stages.
Precursor stages of polymers are known, for example, from German Pat. No. 2 308 830 and its corresponding U.S. Pat. No. 3,957,512. These polymer precursor stages are polyaddition or polycondensation products of polyfunctional carbocyclic or heterocyclic compounds which carry radiation-sensitive radicals, with diamines, diisocyanates, bis-acid chlorides or dicarboxylic acids. The compounds carrying radiation-sensitive radicals contain two carboxyl, carboxylic-acid chloride, amino, isocyanate or hydroxyl groups suitable for addition or condensation reactions and radiation-reactive groups which are bound to carboxyl groups &lt; . . . &gt; partially in ortho- or peri-position thereto &lt;in ester fashion&gt;. The diamines, diisocyanates, bis-acid chlorides and dicarboxylic acids to be reacted with these compounds have at least one cyclic structure element.
The known polymer precursor stages serve for the preparation of protective and insulating layers, as well as the production of relief structures of highly heat-resistant polymers, into which the precursor stages are converted by exposure and, optionally, subsequent annealing. In the process, particularly polymers of the following classes of materials are obtained: Polyimides, polyamidimides, polyester imides, poly-1,3-quinazoline-2,6-diones, poly-isoindoloquinazoline diones, poly-1,3-oxazine-6-ones and polybenz-1,3-oxazine-2,4-diones.